HEALTH INSURANCE COVERAGE FOR PENNSYLVANIA DAIRY FARM MANAGERS

A survey of more than 1200 Pennsylvania dairy farm managers showed that almost 20% of those managers do not have health insurance. Of those farm managers with health insurance, 67% had insurance acquired through the farm business. Farm characteristics and demographic information were used to determine indicators of health insurance coverage. Age, education, net farm income, off-farm income, milk marketing cooperative membership, and intensity of hired labor use all had significant effects on the likelihood of having health insurance and on whether such insurance was provided by the farm business.Agribusiness, Health Economics and Policy,

Surface-cooling effects on compressible boundary-layer instability

The influence of surface cooling on compressible boundary layer instability is discussed theoretically for both viscous and inviscid modes, at high Reynolds numbers. The cooling enhances the surface heat transfer and shear stress, creating a high heat transfer sublayer. This has the effect of distorting and accentuating the viscous Tollmien-Schlichting modes to such an extent that their spatial growth rates become comparable with, and can even exceed, the growth rates of inviscid modes, including those found previously. This is for moderate cooling, and it applies at any Mach number. In addition, the moderate cooling destabilizes otherwise stable viscous or inviscid modes, in particular triggering outward-traveling waves at the edge of the boundary layer in the supersonic regime. Severe cooling is also discussed as it brings compressible dynamics directly into play within the viscous sublayer. All the new cooled modes found involve the heat transfer sublayer quite actively, and they are often multi-structured in form and may be distinct from those observed in previous computational and experimental investigations. The corresponding nonlinear processes are also pointed out with regard to transition in the cooled compressible boundary layer. Finally, comparisons with Lysenko and Maslov's (1984) experiments on surface cooling are presented

Some exact results for the velocity of cracks propagating in non-linear elastic models

We analyze a piece-wise linear elastic model for the propagation of a crack in a stripe geometry under mode III conditions, in the absence of dissipation. The model is continuous in the propagation direction and discrete in the perpendicular direction. The velocity of the crack is a function of the value of the applied strain. We find analytically the value of the propagation velocity close to the Griffith threshold, and close to the strain of uniform breakdown. Contrary to the case of perfectly harmonic behavior up to the fracture point, in the piece-wise linear elastic model the crack velocity is lower than the sound velocity, reaching this limiting value at the strain of uniform breakdown. We complement the analytical results with numerical simulations and find excellent agreement.Comment: 9 pages, 13 figure

G08-1489 Drinking Water Treatment: Activated Carbon Filtration

Activated carbon filtration can effectively reduce certain organic compounds and chlorine in drinking water. It can also reduce the quantity of lead, dissolved radon, and harmless taste- and odor-causing compounds. This 2008 NebGuide discusses the principles, processes, and requirements of activated carbon filtration systems for the domestic (household) user

The Marshes of Back Bay, Virginia

An inventory was undertaken to determine the type and extent of the emergent tidal wetlands in Back Bay, which, historically, has ranged from a lunar tidal brackish estuary to a wind tidal freshwater system. The inventory was conducted primarily by boat with visual observations made for each marsh. The configuration and areal extent of each marsh was determined from USGS topographic maps and confirmed with aerial photography where necessary. Approximately 9925 acres of wetlands as defined by the Commonwealth of Virginia were identified within the watershed. These wetlands supported a very diverse flora consisting of over 109 species. The five dominant species accounted for almost 75% of the wetland acreage. They included: cattails, Typha spp., (4004 acres), needlerush, ]uncus roemerianus, (2371 acres), big cordgrass, Spartina cynosuroides, (605 acres), saltmeadow hay, Sp.artina patens, (449 acres) and switchgrass Panicum virgatum, (427 acres). The remainder of the species represented a diverse mixture of brackish plants with a significant component of freshwater species. The emergent tidal wetlands are dominated by plants typically indicative of brackish conditions even though the system now tends toward freshwater conditions under normal circumstances. These brackish species are probably relicts from when Back Bay was directly influenced by the salinity and tides afforded by inlets to the ocean. The brackish communities because of their continued dominance appear to be more adaptable to the periods of freshwater than the freshwater species are to periods of brackish conditions. These historical oscillations between brackish and fresh conditions are probably responsible for much of the plant diversity found. These plant communities are not static either, as evidenced by changes in the coverage of common reed, Phragmites australis, which has increased substantially between this inventory done in 1977 and recent (1990) observations